Beijing Computational Science Research Center, Beijing, 100193, China.
Department of Conservative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-Sen University, 510055, Guangzhou, Guangdong, China.
Sci Rep. 2019 Jan 28;9(1):804. doi: 10.1038/s41598-018-37170-w.
Recovery of multispecies oral biofilms is investigated following treatment by chlorhexidine gluconate (CHX), iodine-potassium iodide (IPI) and Sodium hypochlorite (NaOCl) both experimentally and theoretically. Experimentally, biofilms taken from two donors were exposed to the three antibacterial solutions (irrigants), respectively, for 10 minutes. We observe that (a) live bacterial cell ratios decline for a week after the exposure and the trend then reverses beyond the week; after fifteen weeks, live bacterial cell ratios in biofilms fully return to their pretreatment levels; (b) NaOCl is shown as the strongest antibacterial agent for the oral biofilms; (c) multispecies oral biofilms from different donors showed no difference in their susceptibility to all the bacterial solutions. Guided by the experiment, a mathematical model for biofilm dynamics is developed, accounting for multiple bacterial phenotypes, quorum sensing, and growth factor proteins, to describe the nonlinear time evolutionary behavior of the biofilms. The model captures time evolutionary dynamics of biofilms before and after antibacterial treatment very well. It reveals the important role played by quorum sensing molecules and growth factors in biofilm recovery and verifies that the source of biofilms has a minimal effect to their recovery. The model is also applied to describe the state of biofilms of various ages treated respectively by CHX, IPI and NaOCl, taken from different donors. Good agreement with experimental data predicted by the model is obtained as well, confirming its applicability to modeling biofilm dynamics in general.
本研究采用葡萄糖酸氯己定（CHX）、碘-碘化钾（IPI）和次氯酸钠（NaOCl）三种抗菌溶液（冲洗剂）对来自两个供体的多菌种口腔生物膜进行实验和理论研究，以探讨其在治疗后的恢复情况。实验中，将生物膜分别暴露于三种抗菌溶液中 10 分钟。我们观察到：（a）在暴露后的一周内，活细菌细胞比例下降，一周后趋势逆转；十五周后，生物膜中的活细菌细胞比例完全恢复到预处理水平；（b）NaOCl 是口腔生物膜最强的抗菌剂；（c）来自不同供体的多菌种口腔生物膜对所有细菌溶液的敏感性无差异。基于实验，我们建立了一个生物膜动力学的数学模型，该模型考虑了多种细菌表型、群体感应和生长因子蛋白，以描述生物膜的非线性时间演化行为。该模型很好地捕捉了抗菌处理前后生物膜的时间演化动态。它揭示了群体感应分子和生长因子在生物膜恢复中的重要作用，并验证了生物膜来源对其恢复的影响最小。该模型还应用于描述分别来自不同供体的用 CHX、IPI 和 NaOCl 处理的不同年龄的生物膜状态，同样得到了与模型预测的实验数据的良好吻合，证实了其在一般生物膜动力学建模中的适用性。
